 Note to plugin users: This problem statement contains images.
Farmer John has several pastures, each of which can be described as several overlapping and/or touching rectangles. For instance, the pasture in the picture below can be considered as the union of the rectangles (2,2)(10,5) and (7,1)(9,7). Two rectangles that only touch each other in a corner aren't counted as touching or overlapping rectangles, see example 4.
Farmer John wants to enclose all his pastures with fences (one fence for each pasture). Help him find out the total
length of all fences if all the borderlines must be fenced (see example 2).
Create a class Fences containing the method fenceLength that takes a int[] x1, a int[] y1, a int[] x2 and a int[] y2, describing the rectangles that make up the pastures by overlapping and/or touching, and returns an int, the total length of all fences. Element i in x1, y1, x2 and y2 describe one rectangle with the opposite corners x1,y1 and x2,y2.

 {976,823,228,463,702,515,690,252,153,
525,260,356,435,369,942, 59,605,173,
178, 70,420, 40,705, 38,841,430,965,
312,680,188,982,160,395,219,340,225}  {314,759, 67,232,815,882,211,839, 48,
531,567,803,439,418,968, 74, 88,834,
806,920,920,194,602,436,624,331,314,
68,421,659,653, 99,921,339,865,408}  {835,794,980, 90,808,649,198,334,309,
749,187,965,578,199,655,273,503,489,
167,996,212,355, 34,430,749,527,109,
501,380, 36,641,872, 47,157,433, 85}  {306,421,283,413,466,747,882,297,790,
576,695,102,655,121, 82,400, 36,236,
143,108,862,400,357,386,790,732, 4,
800,316,166,239,242,121, 57,111, 85} 
 Returns: 3854  
